Automatic control for tabulating machines



Oct. 4, 1938. G. v. A. MALMROS ET AL I 2,131,916

AUTOMATIC CONTROL FOR TABULATING MACHINES Filed Sept. 27, 1934 s Shets-Sheet 1 IOI 100a 7 100 Oct. 4, 1938. G. v. A. MALMROS ET AL 2,131,916

AUTOMATIC CONTROL FOR TABULATING MACHINES 5 Sheets-Sheet 2 Filed Sept. 27, 1934 INVENTOR.

ATTORNEY Oct. 4,1938.

G. V. A; MALMROS ET AL AUTOMATIC CONTROL FOR TABULATING MACHINES Filed Sept. 27, 1934 3 Sheets-Sheet 3 125 "1 0 12a nun! |1@ INVENTOR. d

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ATTORNEY Patented Oct. 4, 1938 I UNITED STATES 2,131,916 AUTOMATIC CONTROL FOR TABULATING MACHINES Gustav V. A. Malmros, Binghamton, and Victor 0. Wilkerson, Vestal Gardens, N. Y., assignors to International Business Machines Corporation, New York, N. York Y., a corporation oi New Application. September 27, 1934, Serial No. 745,694

11 Claims. (01. 235-81.?) I

This case relates to card controlled accounting machines.

Such machines provide a group control which functions to continue normal accounting operas tions so long as cards 01 the same group are pass ing throughthe machine. When a group is exhausted, it is desired to take certain totals 01' the items of said group and to perform a resetting operation. To sense the fact that the cards running through the machine are of the same group, it is known to provide upper and lower card analyzers which sense selected group classifying columns of successive cards. exhausted, the next card will not have the same classifying data and consequently the upper and lower group sensing analyzers will detect the difference and operate group control means to cause normal accounting operations to stop, total taking and ancillary operations to be eiIected, and resetting to occur.

Further, the cards may be arranged in major groups having common major classifying data and a major group in turn sub-divided into minor groups of cards, each minor group having common minor classifying data. The group control means is then adapted to cause a change in machine operations upon either a change in major or minor groups but to efiect different total taking and ancillary operations according to whether the change is in the major or the minor group. 4

The group control'means usually comprises one or more relays for each group data card column and a plurality of sets of contacts associated with the relays. 1

One difiiculty with such means is the possibility among the multiplicity of contacts oi. one or more of them sticking. Another difllculty with a plurality of relay operated contacts is their/mechanical inertia which slows up their speed oi. operation and requires the tabulating cards to be fed at a correspondingly reduced rate.

Accordingly, the object of the present inven-.

tion is to avoid as far as possible the use of a multiplicity oi relays and contacts in the group control system. I

Further, this object contemplates only one relay and set 01' contacts for all major or minor group control columns instead of one for each such column as was formerly necessary.

Still further, the object is to provide such group control'means as may operate'with greater rapidity than heretofore and therefore permit speedier feed of the cards, thereby reducing the time required for obtaining an accounting result.

The latter object is particularly attained in When a group is l and the present caseby the use 01' transformers reacting to the analysis or the group data columns. It is also an object to operate the one. set of contacts iorithe major or minor group control only when the group changes rather than at each card cycle as was formerly done, thus saving wear and tear on the several parts. i Still another object is to provide simple means for preventing back circuits through the group data analyzer should any other device oi the machine be plugged across the control field.

Other objects will be brought out in the following parts of the description and appear from the drawings.

In the drawings:

Fig. 1 is a circuit diagram of the first form of the invention.

Fig. 2 is a circuit diagram of a second form,

oi the invention.

. .'Fig. 3 shows a circuit for a third embodiment of the invention. I v

r Fig. 4 shows a fourth term of the invention,

Fig. 5 is a diagrammatic showing 01' a transformer element used in the scheme of Fig. 4.

For purposes of illustratio'mthe invention will be explained as applied to the machine disclosed in Patent No.. 1,976,617 butas will appear from the present disclosure, the invention is of more general application. Further, only as much of the machine will be explained as is necessary to an understanding of the present invention.

In' the first form of the invention, the upper and lower brushes are connected to the same side 01' the line. The first form will be described with reference to the circuit diagram (Fig. .1). As shownin this figure, when switch 8 is closed, power is supplied to lines I 0 and II. Connected across these lines is a dynamotor DY, which supplies current ata desired voltage to the plus and minus lines I! and H from which power is obtained to energize the various magnets of the tabulating machine.

To initiate operation 01' the machine. start key ST is depressed to close contacts I! iorming thefollowing circuit:

Circuit A.From line I! through closed cam contacts 16, feed clutch magnet I1, contacts I la,

relay l8, start key contacts it, stop key contacts l9, and through contacts 201: (initially closed) to line I. I

Clutch magnet ll when energized by above cir- A through a motor relay 2| which closes contacts 2|a to connect motor TM across power lines II and II. This sets the motor in motion and as the feed clutch is in, cards will be fed through the machine.

When the first card approaches the lower brushes LB, it closes lower card lever contacts 23. Closing of contacts 23 completes a circuit (see the bottom of Fig. 1) from line l4, through contacts 23, lower card relays LCL, and through lead 26 to line l2. When the first card is closing the lower card lever contacts, the second card is closing the upper card lever contacts 24. Closing of contacts 24 completes a circuit from line l4, through contacts 24, and upper card lever relays UCL to the lead 26 of line I2.

A plurality of such relays LCL and UCL are provided in order to effectively control several sets of contacts. Each set of contacts closed by a relay LCL will be characterized as LCL sufllxed by a letter a, b, 0, etc. Similarly, sets of contacts closed by relays UCL will be marked UCL sufiixed by a letter a, b, c, etc.

The cards feedat definite distances apart so that for a short interval, the card lever contacts are open. During this interval cam contacts 23 and 30 close, and the circuits through relays LCL and UCL are-maintained through these contacts and through holding contacts LCLa and UCLa.

Energization of a relay LCL closes contacts LCLb to by-pass the start key contacts ii. The above circuit A for clutch magnet I1 is then routed through contacts LCLb; cam contacts 3| (which close at this time); and switch 32 (closed for'automatic operation). The start key may now be released and the machine will be in automatic operation as long as certain card conditions are satisfied, as will be hereinafter explained.

The control of the adding mechanism is effected by the lower analyzing brushes LB. There is one brush for each column of the card. The cards each have a plurality of columns across the card and each column has a plurality of index point positions, selectively perforated to represent a designation. When a perforation occurs in the column, at a differential point of the movement of the card past the brush LB sensing the column a circuit is completed as follows:

Circuit B.-From line l4, through make and break contacts 33a and 34a (closing periods of which overlap), contacts LCLd, common conductor 35, brush LB engaging through the card perforation with conductor 35, plug socket 36, a plug connection (not shown) to plug socket 31, through an accumulator control magnet 38, and commonwire 39 to line l2. From socket 31, a branch circuit is formed through contacts 40 and printing magnet 42 to common line 39. The manner in which the magnets 38 and 42 respectively control accumulating and printing or listing operations in accordance with the item represented by the analyzed perforation can be understood from aforesaid Patent No. 1,976,617.

As long as cards of the same selected group or classification are passing through 'the machine, the item accumulating and printing operations will automatically continue. Certain columnsof'.

the card are selected for minor group classification and a difierent group of columns ares'elected for major group classification. If the minor group classification changes the machine ft will automatically print a total of the items-accumulated from this group. If the major group classification changes, the totalof all the minor group items will be printed.

Assume that columns 1 and 2 are selected for minor group control and columns 3 and 4 for major group control. Connections 43" are then made from plug sockets 44 connected to the upper brushes UB sensing the selected columns I to 4 of the card to plug sockets 45 and connections are also made from the lower brushes LB traversed by the selected columns to plug sockets 46. The brushes LB and U3 sensing the same card column will be connected respectively to plug sockets 4t and of the same transformer T. The transformers which, in the present example, are connected to the brushes of coluznns l to 4 are respectively marked, for convenience, Col. 1, Col. 2, Col. 3, and Col. 4-. The index point positions of the upper and lower cards pass brushes UB and LB in unison so that as long as the group classifying designation of the same column of the upper and lower cards is the same, the upper and lower brushes will simultaneously feel perforations representing said classification data. Since the cards are in motion, the sensing of a perforation is momentary and as a result a surge of current, corresponding to an alternating current wave, is sent through one of the primary windings 43 and 43 of a transformer T. The circuit through primary winding 48 is as follows:

From line l4, through make and break contacts 33a and 340, contacts UCLd, common conductor 350, brush UB (engaging through a perforation with conductor 350) connection 43, soclcet 45, primary winding 48, and through common lead 50 to line l2.

The circuit through primary winding 43 is made as follows:

From line l4, through make and break contacts 33a and 34a, contacts LCLd, common conductor 35, brush LB (engaging conductor 31 through a perforation in the lower card), a connection to plug socket 45, primary winding 40, and through common lead 50 to line l2.

The current fiows through coils 43 and 43 in opposite directions. Hence, to produce opposing fluxes, the coils are wound in the same direction. When simultaneously energized, the coils will produce oppositely directed fluxes which will neutralize each other and have no effect on the secondary winding 52 of the transformer. Thus, as long as the class data on upper and lower cards agree, secondary windings 52 will remain inert and no change in machine operation will occur.

It is important that the upper and lower brushes of the same column sense perforations of the same value and therefore in corresponding index point positions in exact. synchronisma The upper and lower cards may, however, not be feeding in perfect synchronism because of unequal slippage of the card relative to the feeding means or for some other reason and as a result one of the brushes would sense a perforation in one card before the other brush senses a like perforation in the other card.

As the reaction of the primary winding to the sensing of a perforation by a brush is extremely "rapid, one of the primary windings might, therefore; be energized before the other and as a result, secondary 52 of the same transformer Make and break contacts "a and 340 are operated by notched disks 33 and. There is one notch in each disk for each index point position of a card column. When the contact blades'fl' and 34' drop into a notch, the contacts 33a and 34a close. Thus during rotation of a disk, the contacts will make and break as many times as there are ndex point positions in a card column. The disks 33 and are so timed with respect to each other that one of the contact blades 33 or 34' will move into and out of a notch before the other contact blade but for an instant they will both be in notches at the same time so that the circuits through contacts 830 and 34a in series can be made at a sharply defined momentary point of the cycle falling within the sensing periods of like index point positions of the upper and lower card levers by the upper and lower brushes. The circuits through primary windings 48 and 49 are therefore timed by make and break contacts 33a and 34a to make in exact synchronism.

It may be well, at this point, to explain the theory of operation as it relates to the inducing of a current flow and the direction of current flow in the transformed secondary. The dynamotor DY, in the present case, supplies direct current to opposite lines I2 and I4. When the brush at an analyzing station is on an unperforated or dead portion of a card, there is no circuit formed therethrough. When the brush moves into a perforation and engages the common conductor of the analyzing station, a circuit, such as traced hereinbefore, is formed through the connected primary 48 or 49. Although the primary current is direct current, the fact that the latter starts at zero (or a minimum) at the moment the circuit makes and increases to its maximum value as the circuit is fully made produces a fluctuating current impulse. This current fluctuation is a rising current, threading both primary and associated secondary with an increasing flux. The increasing flux induces an E. M. F. in the secondary to produce a current flow therein in a certain direction. After the primary circuit was fully made, the primary current fluctuation stops and a constant flux is threading the transformer coils so that no current is induced or flowing in the secondary. When the primary circuit breaks, due to the perforation leaving the brush orthe opening of contacts 33a and 34a, the flux thread- ,ing the transformer windings collapses, causing an induced current to flow in the secondary in a direction opposite to the direction of flow during the building up of the flux.

For practical purposes, and in the ultimate effect on control of the machine, only. the current induced by the building up of the flux need be considered as thisoccurs flrst, because of the brush moving into a perforation, and takes effect before the occurrence of the induced current resuiting from the collapsing flux. Accordingly,

consider, for the present, only the results of the brush moving into a perforation with consequent increasing flux threading the transformer windings.

Assume now that'a change in the minor group classification occurs. As a result, the upper and lower brushes do not simultaneously sense perforations. Consequently one or the other of the brushes feeling the'same minor classification column sends an impulse through the connected primary winding while the other brush does not send an impulse to its connected primary winding. The impulse thus sent is an, increasing current tion items do not' agree.

flow which causes a fluxlto build up, threading the primary connected to the active perforation feeling brush.

Since only one primary winding is energized a current is induced in one direction in the secondary winding. Thus if primary winding 4| is energized, then a current will be induced in' secondary 52 which will be-in a direction which, for convenience, may be referred to as the forward direction permitting its passage through a rectiher 53 while if primary 48 is energized,- the current induced in secondary 52 will be in a direction which, for convenience, may be called the reverse direction permitting its passage through a uni-directional current valve or rectifier I4. The

rectiflers may be of any, suitable type such as of vacuum tube, photocell, crystal, or dry copper oxide disk type. Assume that the upper brush is sensing a perforation while the lower brush is not, then primary 48 will be energized to induce current through secondary 52 to form the following circuit:

From one end of secondary 52, through rectifler 53, pick-up coil 55 of a duo control. relay R; plug socket 56, plug connection 51, and through serially connected plug socket 58 to the opposite end of' the secondary l2.

Should the lower brush be sensing a perforation while the upper brush is not, then the circuit will be as follows: I

From one end of secondary 52, through plug sockets i8, connection 51, the other pick-up coil 0 of the relayR, and through rectifier 54 to the opposite end of the secondary.

The purpose of the rectifler's is to prevent perforations of like value in different card columns from neutralizing each other'scontrol of the relay R. For example, with number 13 perforated in columns I and 2 of the lower card and number 31 in columns I and 2 of the upper card, the relay It would not beactivated in the absence of the rectiflers although theseclassiflca- To understand this, consider column I alonewith the upper brush sensing a "3 in the column whilethe lower brush is dead, resulting in energization of the primary coil 48 of column .I transformer T at the 3" point of the card reading cycle. The primary coil 48 will thereupon induce a current in one direction in its secondary 52. With absence of rectiflers, this secondary will send .current through both coils 55 and 550 of relay R in one direction. At the same time, if a lower brush is sensing a "3" in column! of the lower card while the upper brush of column 2 of the upper card is dead, then primary 4!! of column 2 transformer will be energized, inducing current in its secondary 52 in opposite sense to the current induced in column I secondary I2. Column I secondary will therefore send current through both coils 55 and 550 in an opposite direction to the current in said coils flowing from the secondary of column I transformer. The opposing currents will neutralize each other and the relay R wil not be activated .as it should be'on a change in a minor classification data. By using rectiflers 53 and 54 in above example, current from column I transformer is allowed to pass only by rectifier 53 resulting in energize tion of coil 55 alone while current from column 2 transformer can pass only through'rectifler 54 to energize coil 55!! alone.

While the currents in these coils are in opposite sense, the fact that they are oppositely wound causes their energization to assist each other.

glad to close contacts Ilia to Energization of coil 55 or 550 or both, results in closing holding contacts 62 and opening minor control contacts 68.

Closure of contacts 62 forms a circuit through holding coil 84 of minor control relay R as follows: I

From line I2, through wire 50, contacts 82, coil 64', and cam contacts 66, to line I4.

, Energization of coil 84 holds contacts 62 closed and contacts 83 open until cam contacts 68 break near the end of the card cycle.

In a similar manner, when major classification items in selected columns 3 and 4 do not agree, then current will flow from the secondaries of transformers T of columns 3 and 4 through plug wire 51 to socket 56' of major control relay R and the latter will act to close contacts 82' and open contacts 63'.

The currents flowing in the secondaries as a result of the fluxes building up when the brushes move into perforations to make the primary circuits havebeen considered above. In practice, only these currents are important as they occur first and result in energization of holding coil 84 and opening of control contacts 63 and/or 63' before the primary circuits break.

When the primary circuit breaks, the flux threading the secondary collapses, inducing a current thereinin the opposite direction to that of the current previously induced. by the increasing flux. Considering only the minor control relay R, with opening of the primary circult through primary 4!, the collapsing flux induces a current flow in the associated secondary 52 in the direction previously characterized as reverse. This reverse current flows through rectifier B4 to relay coil "Ii. With opening of the primary circuit through primary 49, the current induced in the secondary is in the forward direc tion, which through rectifier II, flows. through relay coil II. Energization of one or both coils and "Ii results, tending to open contacts 6!. But the latter contacts are already open because of previous energization of the coils due to the building up of flux in the transformers, so that the later energization of the coils is without any practical result.

Only when both the major and minor group classifications on successive cards agree, willcontacts 01 and 83' remain closed. These contacts are in series and if either is open during the card cycle, a change in machine operation will occur, as will be hereinafter described.

Initially the circuit through control relay 20 is momentarily made as follows when cam contacts and 61' close for a brief interval:

Circuit C.--From line I 2, through cam contacts 61,switch 68, cam contacts 61', relay I0,

relay II, line I2, control relay", line 13, terminal Ill, cam contacts 14 and N, terminal I60 and lead 18 to line I4.

When above circuit makes, magnet I0 is enershunt out cam contacts 41 and 61'.

Cam contacts I4 and I! open for abrief interval of each card cycle after the item perforation positions of thecards have passed the analyzing brushes. When cam contacts "and I5 open, circuit C must be maintained through minor control contacts 83 andmajor control contacts 63. The shunt path of circuit C through the major and minor control contacts is as follows:

From terminal I30, through line 11, minor control contacts 63, lines 18, I9, major control contacts 88', line III, and through contacts UCLe, to terminal 160.

Briefly, circuit C which energizes control relay 20 is initiated by momentary closure of cam contacts 61 and 61'. The circuit energizes relay III to close contacts 10a and by-pass cam contacts 61 and 61'. During the period of the cycle in which the brushes search for classification data, the circuit is established through cam contacts I4 and 15. After the searching period, the cam contacts I4 and 15 open and the circuit must be made through major and minor control contacts 63 and 6!, respectively. However, if during the searching period, a disagreement in minor classification data has occurred, then as above explained, minor control contacts '3 open and the circuit is broken. Or if a major group change has occurred, the major control contacts 81' open and circuit C is likewise broken.

With circuit C broken, then relay 20 is deenergized and its contacts 2011 are open. Accordingly, circuit A is broken and clutch magnet I I and motor control relay 2| are deenergized. Motor TM will therefore stop and the card feed will be interrupted.

The deenergization of relay 20, which occurs upon the group change, as above explained. causes contacts 20a to open and contacts 201) to close. Now with switch RS closed, the following circuit is formed:

From line I4 through contacts 20b, switch RS, cam contacts I! (momentarily closed near the end of the cycle) magnet 83, and closed cam contacts 84, to line I2.

Magnet II is thereby energized and closes contacts 83a connected through line I. directly to line I4 to shunt out cam contacts l2, switch R8,

and contacts 20b. When a minor group change occurred, circuit C wasopened and magnet II in this circuit was deenergized, thereby permitting contacts Ila (above cam 84) to close. With both contacts Ila and "a closed the following circuit is made: a

From line I2, through contacts Ila, normally closed contacts 81, reset clutch magnet ll, clam cam contacts 09, contacts a, and line lead Ii, to line I4.

Energization by above circuit of reset clutch magnet 88 connects the reset motor RM to the read out, total printing, zeroizingmechanisms to operate as explained in aforesaid I Patent No. 1,976,617. Magnet Cl also closes contacts Ila to form the reset motor circuit as follows:

From line III, through reset motor RM, magnet 92, lilne 93, contacts "a, line 84, and line 95, to line I.

' This circuit causes operation of the reset motor.

Shortly after the reset motor starts on its cycle,

cam contacts 90 close to shunt out contacts Ila.

As explained above, a change in minor classification opened circuit C by causing minor control relay R to open minor control contacts 88. Consequently, relay III in circuit C is deenergized and contacts Illa open. Circuit C can now be reestablished only through its initial path which is through cam contacts 41 and 61'; These latter close near the end of the reset cycle and circuit C is again made so'that magnet II is energized to open contacts Ila. i v

Cam contacts 84 also open at this timeso that 'the circuit through reset clutch magnet il and relay magnet 83 will be broken. Consequently,

the reset and totaling mechanism will be declutched irom the reset motor RMand contacts 800 willopen to break one of the circuit paths through the reset motor. The reset mechanism coasts to home position and at the end of its one cycle, causes cam contacts 96 to break, opening the remaining circuit path through the reset motor.

During the reset cycle, the printing of only the minor totals from selected accumulator banks and the zeroizing of the latter takes place in a manner detailed in aforesaid patent.

When a major group change occurs, not only is the minor total taken but also the printing of major total from selected accumulator banks and their zeroizing is effected. When a change in major group control takes place, major control relay R is energized, opening contacts 63' which thereupon breaks circuit C. As a result, the reset and minor control operations take place in exactly the same.manner as before explained. At the same time, opening or contacts BI breaks a circuit through a'control relay I00. This cir-v cuit had been initiated by closure of cam contacts 6! in the preceding reset cycle, as follows:

From line I2, through contacts 61, relay I00, terminal IOI, cam contacts I5, terminal I60, and through lead I6 to line I 4.

Energization of magnet I00 closes contacts I001: to shunt out cam contacts 61 which shortly thereafter open. When cam contacts I5 open, the circuit through magnet I00 must be completed through contacts 63' as follows:

From terminal IOI, through line I9, contacts 63', line 80, contacts USLe, and to terminal I60.

Should a major group change occur, then major control relay R will open contacts 63', breaking the latter circuit path of relay I00 so circuit C opens. The opening of circuit C results in resetting operations as before explained.

Relay I00 being deenergized, contacts I 00a open and contacts I 00b close. Closing of contacts I00b controls a major total printing operation, in a manner outlined in aforesaid patent.

Figure 2 shows a form of the invention in which the upper and lower brushes are connected on opposite sides of the current supply. Thus, with closure of cam contacts 60, if the upper brush I is sensing a perforation, say 3, in column I of the upper card then the circuit will be as follows:

From plus line I2, through contacts 60', make and break timing contacts 330-I, common conductor 350', column I upper brush UB-I, primary transformer coil I I0, and lead I II to minus line II. If the lower brush LBI is simultaneously with above occurrence sensing a "3" perforation in column I of the lower card, the following circuit will form:

From plus line I2 throughv lead II2, primary transformer coil II3, brush LB-I. common conductor lower card lever contacts III, and make and break timing contacts Mir-I to minus line II.

The function of contacts 330-4 and fla-I is the same as that of contacts 33a and 34a of the first form of the invention.

Coils H0 and H3 are wound oppositely to each other so that with the simultaneous completion of circuits therethrough they will have no effect on secondary transformer coil II5. Should only one brush LB or UB in the same column order be sensing a perforation, then one of coils H0 or I I3 will be active while the other would be inactive and an induced current will form in secondary H5. The connections of the secondary coils to the rest of the machine is the same as in Fig. 1 so that energization of these secondaries cults will form through lower brush will produce a change in machine control and total and reset operations in the-same manner as described in connection with the first form of the invention. I l y In Figure 3 is shown a third form of the invention, in which the upper and lower brushes are on the same side of thecurrent supply and in which .only one primary transformer coil II6 to each transformer ,is necessary foreach pair of correlated upper and lower brushes. This single primary coil II! is placed in the balance line of a Wheatstone bridge arrangement in which resistances r and r are equal. Thus, if the upper and lower brushes of the same column UP and LB are reading perforations of the same value, circuits will form through '03 as follows:

From plus line I2-'-I, through resistance r, rectifier I.I8, plug connection 0, brush .UB', common conductor 300-I, upper card lever contacts I20, and through make and break contacts 330-2 and 340-4, to line I4--I. A second parallel circuit will form from line I2-I through resistance 1'', primary coil II 6, and as before.

This circuit through primary coil H6 is in one direction.

Simultaneously with above circuits, other cir- LB' as follows:

From plus line I2-I, through resistance r, rectifier I I 8', brush LB, common conductor 35-I, lower card lever contacts I2 I, and makeand break contacts 3311-2 and 340-2, to line ll-I. A second parallel circuit is formed from line I2-I through resistance r, primary coil I I6, LB, and as before.

This circuit through primary coil H6 is inthe opposite direction to the previously described circuit through the primary. a I

Resistances r and 1'' being equal, these opposing circuits through I I0 neutralize each other so that coil H6 will not be energized. The Wheatstone bridge is then in {balanced condition. either UB' or LB be sensing a perforation while the other is not, the current in coil H6 is in one direction and not opposed by an opposite current. Consequently, coll IIO will be energized and induce current in secondary I22. The connections of the secondary to the rest of the machine are the same as in Fig. -1 so that itsenergization will produce the same results as in the first form of the invention.

Rectifiers H8 and H8 are provided in the primary circuits to prevent back circuits when other. devices of the machine are plugged across the control field to the group control analyzing brushes.

Figs. 4 and 5 show still another form of the invention. In this form, the 'duo control relay R-I does not require a double pick-up winding such as 55 and 550 of duo control magnet R of Fig. 1. This is because the current induced inthe secondaries of the transformer is in only one direction regardless of whether the upper or lower brush is the active one.

Therefore, should a lower brush in one column be sensing the same value perforation as an up-' per brush in another column, then the currents induced in the secondaries of the different corresponding transformers will flow in the same direction through the single activating coil of the control relay.

To understand the above, consider first the circuits when the upper and lower brushes UBA and LB-A are sensing the same value perforation in the same column of the upper and lower cards.

Should i A circuit will form through the upper brush as follows:

From plus line I2-2, through common line I24, primary winding I25, plug connection I26, upper brush UB-A, common conductor 350-2, line I21, and make and break timing contacts 330-3, to minus line I4-2.

One circuit through lower brush LB-A will be from plus line I2-2 through make and break timing contacts 34Gr-3, common conductor 35-2, brush LB-A, rectifier I28, and primary winding I29 to minus .line I42. Another circuit through LB-A will be from plus line I2-2, through contacts 340-3, conductor 35-2, brush LB-A, primary coil I30, connection I26, UB-A,

conductor 350-2, line I21, and contacts 330-3,

to minus line I4-2. Coils I25 and I29 are wound in the same direction but opposite to the direction of winding of coil I30, thus with agreement in the same column, coils I25, I29 and I30 will all be energized and the direction of flux produced by the current in each will be as indicated by the arrows in Fig. 5.

When the coils I25, I29, and I30 are singly energized upon brushes UB and LB sensing corresponding perforations, the coil I30 is designed to produce a flux balancing the sum of the fluxes of coils I25 and I29. Accordingly, the secondary coil I 32 will not be effectively energized.

When only the upper brush is alive, then the circuit can be made only through coil I25. When only the lower brush is alive, coil I29 alone will be energized. In either case, since both coils produce fluxes in the same direction, the current induced in secondary winding I32 will be in only a single direction, regardless of whether the upper or lower brush is alive. Hence if a lower brush in one column is sensing a 3" perforation simultaneously with the sensing of a 3 perforation by the upper brush of a different column, the current in the secondaries I32 belonging to the different columns will be in the same direction. Thus, the occurrence of a 13 in one card and a 31 in the other card will not counteract each other in their control of the secondaries of the assoe ciated transformers and no one-way valves or rectifiers are needed as in Fig. 1. Hence only one pick-up coil I33 in the group control relay R-I is required.

The only reason for providing rectifiers I34 in the secondary circuits of Figs. 4 and 5, is to prevent the current produced by one secondary coil from flowing back into another secondary coil to-be thereby dissipated. The rectifiers I34 perjmit the current from a secondary I32 to flow fiers, relay I33-620 would have to be designed to operate with a smaller supply of current energy than when the rectifiers are included.

Holding coil 640, cam contacts 660, holding contacts 620, and machine control contacts 630 function in the same way as the respectively corresponding elements 54, 66, 62, and 63 of Fig. l. The above explanation of the form shown in Figs. 4 and 5has taken into account only the effects of the increasing fluxes in the transformer windings when the brushes entered the perforations and made the primary circuits. When the primary circuits break, the fluxes threading the transformer windings collapse. If the group control perforations agree, then the decreasing fluxes counteract each other. If the control perforations of corresponding upper and lower card columns disagree, the decreasing flux threading the associated secondary I32 tends to produce a current flow therein in a direction opposed by rectifier I34. Thus, the collapsing flux, resulting from the brush leaving the perforation does not disturb the previous energization of holding coil 640. Even were rectifier I34 dispensed with, the decreasing flux would still fail to disturb the energization of coil 040. Thus, with rectifier I34 omitted, the decreasing flux would produce a reverse current fiow or one in a direction opposite to the direction of the current produced by the increasing current flow. Energization of coil I33 by the reverse current flow would tend to reopen contacts 520. But the holding coil 640, being energized, would maintain contacts 620 closed.

The purpose of rectifiers I28 between the lower brushes LB and the windings I29 and I30 is to prevent the formation of back circuits through the lower brushes when other devices are connected to the lower brushes.

While the invention has been disclosed as embodied in the several illustrated forms, it is understood that variations and changes may be made within the field of mechanical skill without departing from the scope of the invention. We therefore wish to be limited only by the following claims.

What is claimed is as follows:

1. In 'a machine in which cards bearing group designations are run through in groups; the combination of electrical means for comparing the designations of successive cards to detect a group change and including a transformer primary effectively energized upon the detection of a group change, a transformer secondary coupled to said primary and in which current is induced by effective energization of aforesaid primary, and a control device for the machine in series with said secondary and varied in operation by said secondary when current is induced therein upon a group change.

2. In a machine in which cards bearing group designations are run through in groups; the combination of electrical means for comparing the designations of successive cards to detect a group change and including a transformer primary having opposing primary windings simultaneously energized to neutralize each other upon agreement between the designations of said successive cards and singly energized upon nonagreement between the designations denoting a group change, a transformer secondary coupled to said primary windings and in which current is induced by energization singly of said primary windings, and a control relay for the machine in series with the secondary and varied in operation by said secondary when current is induced therein. 1

3. In a machine in which cards bearing group classifying perforations are run through in groups, the perforations of successive cards agreeing except upon a change in group; the combination of spaced analyzers for concurrently sensing agreeing group perforations of successive cards, a transformer including a pair of opposed primary windings, each in circuit with a different one of the analyzers to be energized when a perforation is sensed, both said windings being simultaneously energized upon concurrent sensing of agreeing perforations by both analyzers to neutralize each other, said windings being singly energized upon failure of the analyzers to concurrently sense perforations upon a group change, a secondary in said transformer in which current is induced by the energization of either of said windings singly, a relay in circuit with the secondary and energized by the current flow in the secondary, and means controlled by energization of the relay for varying the operation of the machine.

4. In a machine in which cards having group designating perforations are run through in groups; the combination of analyzers for sensing the group designating perforations of successive cards while the latter are in motion, both analyzers concurrently sensing the perforations if they agree and one orthe other analyzer sensing perforations before the other if the perforations do not agree, a transformer having a primary and secondary with the primary controlled by the analyzers to provide a current flow through the secondary in either of opposite directions in accordance with which analyzer senses perforations first, a pair of relay coils conductively connected to the secondary, uni-directional current valves in series with each relay coil to pass current flow from the secondary to only one of said coils depending on its direction, and means controlled by either relay coil upon its receiving a current flow from the secondary for varying operation of the machine.

5. In a machine in which cards bearing group designating perforations in a plurality of columns are run through in succession; the combination of a series of analyzing brushes one to each group designating column to sense one of a pair of such successively running cards, a second series of analyzing brushes one to ach group designating column to sense the othe of the pair of such successive cards, a plurality of transformers, each having its primary in series with and controlled by one pair of corresponding brushes of both series to produce a current flow in the secondary in either of opposite directions depending on which of the pair of corresponding brushes senses perforations first, a pair of relay coils conductively connected to the secondaries of all the transformers, uni-directional current valves interposed in the circuit between each of the secondaries and the relay coils to direct the flow from any secondary in one direction to one coil and a simultaneous flow from another said secondary in an opposite direction to the other coil, and means controlled by the coils for varying machine operations.

6. The invention as defined in claim 5, said relay coils being oppositely wound to assist each other when simultaneously energized by the reception of oppositely flowing currents from the transformers, and said last-named means including control contacts commonly operated by both said coils.

7. In a machine in which cards bearing group designating perforations in several columns are run'through in groups; the combination of means for analyzing the group designating columns of successive cards to detect a group change, a plurality of transformers, one to each like pair of group designating columns of successive cards, each transformer having a primary and a secondary with the primary controlled by the analyzing means to produce a current flow in the secondary when the analyzing means detects a group change in the like columns of the successive cards corresponding to said transformer, a relay in circuit with all the secondaries and energized by the current flow of any one or more of said secondaries, and means controlled by the relay upon its ,energization to vary machine operation.

8. In a machine in which cards bearing group designations are run through in groups; the combination of means for comparing the designations of successive cards to detect a group change and including a transformer primary and a Wheatstone bridge circuit. having said transformer primary arranged in its balance line, the circuit being connected at opposite sides to the comparing means to be in balance when the comparing means fails to detect a group change whereby the transformer primary remains unenergized when the successive cards belong to the same group, the

circuit being unbalanced upon the comparing means detecting a group change to thereby energize said primary, a secondary coupled to said primary and in which current is induced by energization of the latter, and a control device for the machine in series with said secondary and varied by the current in said secondary.

9. In a machine in which cards bearing group designations are run through in groups; the combination of spaced analyzing brushes for sensing the designations of successive cards, a transformer having a pair of similarly wound primary coils, one in circuit with one of the brushes and the other in circuit with the other brush to be simultaneously energized upon the brushes sensing agreeing designations, a third primary coil wound oppositely to the first-mentioned primary coils and in circuit with both said brushes to be simultaneously energized with the latter coils under control of said brushes when the designations agree to thereby neutralize the combined effects of the latter coils, either one of the first-mentioned coils being energized alone when the brushes sense unlike perforations while the other primary coils remain unenergized, a secondary coupled to the primary coils and in which an E. M. F. is induced by energization of eitherone of said first-mentioned coils alone upon failure of designations to agree, and means controlled by the secondary when energized for varying machine operation.

10. The invention according to claim 9 in which the designations are arranged in several card columns; there being one pair of analyzing brushes for each card column and one such transformer to each pair of brushes/the secondaries of said circuits being arranged in parallel circuit, and uni-directional current valves between the transformer and one side of said circuit to prevent the induced current from one secondary flowing into another. I

11. In a machine in which cards bearing group data are run through in groups; the combination of electrical means to compare group data of successive cards to detect a group change and including a'transformer primary effectively energized upon occurrence of a group change, a transformer secondary in which current is induced by energization of the transformer primary, a unidirectional current valve in series with the secondary, and an electrical control device in circuit with the secondary and valve to which current from the secondary in only one direction is permitted to pass by said valve to energize said VICTOR O. WILKERSON. 

